Active Matrix Organic Light Emitting Diode (AMOLED) panel are applied more and more extensively. The pixel display device of the AMOLED panel is an organic light-emitting diode (OLED). The AMOLED panel emits light by driving a thin film transistor to generate a driving current in a saturated state to drive the OLED to emit light. FIG. 1 is a structural schematic diagram of a pixel driving circuit in the prior art. As shown in FIG. 1, the existing pixel driving circuit employs a 2T1C circuit which includes two thin film transistors (a switch transistor T0 and a driving transistor DTFT) and a storage capacitor C.
However, in the current low-temperature polycrystalline silicon process, undesirable uniformity of the threshold voltages Vth exists among individual driving transistors DTFT on a display substrate and the threshold voltages even drift during use. As such, when a scanning line controls the switch transistor T0 to turn on to input the same data voltage Vdata to respective driving transistors DTFT, uniformity of the luminance of the AMOLEDs may be undesirable due to their different driving currents resulting from the variation of the threshold voltage Vth of the driving transistors DTFT.
In addition, the OLEDs gradually age over time, which leads to attenuation of the display luminance of the OLEDs and in turn affects the user's use.